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Running supply voltage of 60/60 - Vs - 120/Neutral

With the power system im running now, it supplys power at 60 volts and 60 volts each leg, Versus the nominal 120 volt and neautral, im curious as to what the benifits and problems that this may cause for audio equipment, with running no neutral, i get this off of the isolation transformer, as part af a large power system with battery backup to insure than nothing frys in the event of surges and electrical storms, could this possibly cause a better "balance" and maybee increas audio quality? it's definatly a safer system as you would not get shocked unless you touched both legs at the same time.
archangelluke
archangelluke OP
14 posts
 
The grounding system i am using is a common all across system, so the primary and the secondary ground is the same, with normal outlet ground, i am having trouble with ac noise, on my sub (sunfire) it has a humm without any inputs attached, the grounding system may be the reason for it.

heres a pick for one of the transformers i am using, wich is dedicated to my sunfire sub, as it draws up to 2700 watts of ac power:

http://cgim.audiogon.com/cgi-bin/vs.pl?vstrt&1120471223&viewitem&o6

The input has been config for 240v in as thats what my apc runs on, and output taps 5 and 8, this system was made to be tough,mainly becaus of the sunfire high current draw.

Thank you for your help, i will keep posting on this thread as we discuss this matter,
jea48
2,944 posts
 
Bob bundus;
quote
"in addition to improved line transient protection, your balanced AC supply line offers increased common mode noise rejection over the traditional unbalanced commercial power source."

Could you please explain in more detail.....

This being the unbalanced.
A single phase isolation transformer with one of the two secondary output leads bonded to ground. Thus one grounded conductor and one ungrounded conductor, 120V.

This being the balanced.
A single phase isolation transformer with a center tap secondary winding 60/120V,
60V-0-60V. The center tap being bonded to ground. Two 120V ungrounded conductors with a reference voltage potential to ground of 60V each.
sean
6,229 posts
 
Some of the Sunfire subs are notorious for being noisy. You should contact Sunfire about this problem and discuss it directly with them.

As to the isolation transformer pictured, it looks WAY too small to pass 2000 KVA with low distortion. Then again, it is hard to judge how big the core actually is going by that picture, as there are only the wires and heads of the bolts holding it together to gauge the physical features by. This wouldn't introduce hum into the sub at idle, but it could introduce other distortions at higher power demands. Sean
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jea48
2,944 posts
 
"The input has been config for 240v in as thats what my apc runs on, and output taps 5 and 8, this system was made to be tough,mainly becaus of the sunfire high current draw."

"apc", Apartment
"taps 5 and 8" >>> #5 = 0, #8 = 115V output.
=============================================

"The input has been config for 240v"

Then #2 & #3 tied together? With the 240V supply connected to terms #1 & #4?
=============================================
2000VA
Agreed more than likely xfmr is to small.
Max safe load of xfmr 2000 x 80% = 1600VA

Check the output voltage of the xfmr with the load connected. The load being the Sub

Jim
sean
6,229 posts
 
The Sunfire amps are quite efficient by design, so they don't pull much current at idle or even during normal use. The only time that they really pull BIG power is when you're throttling the volume with heavy bass passages. As such, the small core Iso transformer wouldn't be causing the hum at idle, which is what Luke has alluded to. Sean
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